Spark-coil.



D. M. BLISS.

SPARK COIL.

APPLICATION FILED Dec. 7, I9Io.

1,174,225. Patented Mar. 7,1916.

UNITED `STATES PATENT OFFICE.

DONALD M. BLISS, F WEST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- A.I YIIENTS, T0 THOMAS A. EDISON, INCORPORATED, 0F WEST ORANGE, NEW JERSEY,

A CORPORATION OF NEW JERSEY.

SPARK-COIL.

Specification of Letters Patent.

Patented Mar. 7, 1916.

Application ined December 7, 1910. serial Ne. ssaos?.

To all whom t may concern.'

- the following is a description.

My invention relates to spark vcoils such as are used in sparking gas engines, par? ticularly of the make and break type, but it is also adapted to be applied to other uses, for example, to small transformers for bell ringing circuits and other low voltage work.

More particularly my invention relates to a construction comprising iron stampings or laminas of a novel type for the magnetic field of a coil and to a casing designed to hold these stampings in place without the use of rivets, screws `or a mass' of insulating material. y

My invention comprises a casing having a body portion provided with integral means for supporting the stampings against downward .movement and for maintainin them in contact or properly spaced, and a" cover for said body portion engaging the" stampings and holding them irmly in place within the casing.

In the form of my invention disclosed, I provide the body portion of the casing with integral projections in the form of ribs hav- Alng enlargements onwhich the stampings rest, the ribs coacting with the stampings to hold theml in proper relation to each other. I also provide additional projections having horizontal seats to assist in supporting the stampings.

My object is to reduce the cost of construction j and simplify the design in devices of this character and to provide an easily made and readily assembled device of relatively high eiiciency.

In order that my invention may be more fully understood, attention is hereby directed to the accompanying drawings forming part of this specification, and in which:

Figure 1 is a central longitudinal verticalsection of my improved spark coil taken on the line 1-1 of Fig. 3; Fig. 2 is a cross section thereof taken on the linel 2 2 of Fig. 3; Fig. 3 is a horizontal section thereof taken on the line 3-3 of Fig. 1; and Fig. 4 is a detail in section on the line Jell of Fig. 3.

In all the views like parts are designated by the same referencenumerals.

Referring-to the drawings, l and 2 are two sets of E-shaped iron stampings, each set comprising a number of laminated members loosely assembled on top of each other to the proper thickness to firmly support on their central cores 3 and 4 respectively, a coil 5 of insulated wire. As shown in Fig. 3, coil 5 passes into the slots between the parallel arms and the central cores of the stampings, which latter are made of a size to .adapt the coil to the particular use to which it is to be put. When it is to beused as a spark coil for gas engines, I prefer to open the magnetic circuit slightly by making the arms and the cores of the stampings of such a length that when the stampings are assembled in place within the casing 6 there is an air gap 7 of predetermined length between parts 1 and 2, so that the coil will operate more rapidly than if the magnetic circuit were completely closed. When using the device as a small transformer or on alternating current circuits, the arms and cores of the stampings are made of such a length that the two sets of stampings will be in magnetic contact with each other.

Thevcasing for the coil and the stampings comprises a rectangular cast metal body portion 8 and cover 9 therefor. The body portion is provided centrally at each side with a projection in the form of a vertical rib 10 having an enlargement 11 on its lower portion and with projections 12, each located in one of the corners of the body portion. The enlargements 11 and projections 12 are each provided with a horizontal seat, all of the horizontal seats being preferably in the same plane and serving to support the stampings firmly. The lower surfaces of the enlargements 12 are Hush with the bottom of the body portion. Recesses 13 aud 13 are formed in the edges of the stampiugs centrally of the portions connecting the arms and cores and at the ends of the arms respectively, the recesses being adapted to engage the vertical ribslO to hold the Stampings in their proper relative positions on the horizontal seats of the e11- largements and corner projections.

The cover 9 is made ot' resilient material and as shown at 14: and 15 Fig. 1, compresses the edges ot the stampings; so that, when it is fastened in place on the body portion S b v the screws 16, it holds the siampiugs and the coil carried thereby lrmly in position. Binding posts 17 and 1h of a well known type, are secured to the body portion aml are adapted to connect the ends of the wire of the coil with a circuit containing a source of current supply. l'n order that the device may be secured upon the desired support, the body portion is provided with perforated ears 19 and 20.

In assembling my improved apparatus, it is simply necessary to superpose the stamp# ings on each other to the proper thickness, to place the coil of wire on the central cores of the stampings, to slide the coil and the stampings into position in the body portion, to fasten the ends of the wire of the coil to the binding posts, and to secure the cover in place. This being done, the stampings are held rigidly in place by the projections described above and by the cover'for the casing.

It is evident that numerous changes may be made in the construction described above without departing from the spirit of my invention. Instead of using a cast metal casing. I may use a sheet metal casing with the projections pressed therein so as to lighten the weight and further reduce the cost of the construction. I may also ll the entire space within the casing with some insulating water-proof compound so as to adapt the coil for use in damp places. The 'insulating compound in this case does not serve to hold the stampings in place, but simply acts as a medium of insulation.

Having now -described my invention, wha I claim and desire to secure by Letters Patent of the United States is:

1. In electrical apparatus, the combination of a casing comprising a body portion having inwardly extended projections forming vertical ribs and having horizontal seats, and a cover secured to the body portion, and a plurality of superimposed lamimc having recesses registering substantially vertically, said laminae being clamped in piles upon said seats by the cover and said ribs engaging recessed portions of said lamin to position said lamina. substantially as described.

2. In electrical apparatus, the combination ot' a casing comprising a body portion having inwardly extended projections forming vertical ribs and having horizont-al seats, and a resilient cover secured to the body portion, and a plurality of superimposed lamimc having recesses registering substantially vertically, said lamina: being clamped in piles upon said seats by the cover and said ribs engaging recessed portions of said laminae to position said laminas, substantially as described.-

3. In electrical apparatus, the combination of a casing comprising a rectangular body portion having at each corner an inwardly extended projection provided with a horizontal seat and having intermediate of said corners inwardly extended projections forming vertical ribs and having horizontal seats, all of said seats being in the same plane, and a cover secured to the body portion. and a plurality of superimposed laminae having recesses registering substantially vertically, said lamin being clamped in piles upon said seats b v the cover, and said ribs engaging recessed portions of said lamin to position said laminae, substantially as described.

4. In electrical apparatus. the combination with a coil of wire, of two sets of vertically grooved superimposed laminac. each set having a portion extended into said coil, and a casing having a plurality of projections thereon, said projections including projections having horizontal seats to support said laminae and projections forming vertically extending ribs engaging grooved portions of said laminae to retain the same in proper relation to each other, substantially as described.

5. In electrical apparatus, the combination with a coil of wire, of two sets of vertically grooved superimposed laminar, each set having a portion extended into said coil, said extended portions being separated by an air gap across the magnetic circuit of said coil, and a casing having a plurality of projections thereon, said projections including projections provided with horizontal seats to support said laminae and projections forming vertically extending ribs engaging grooved portions of said laminac to retain the same in proper relation to each other, substantially as described.

6. In electrical apparatus, the combinaytion with a coil of wire, of two sets of vertica-lly grooved superimposed E-shaped laminae, the legs of one set being extended toward but spaced by an air gap from the legs of the other set. the central leg of each seL being extended into said coil. and a casing including a body portion havingv a plurality of projections thereon, said projections in- This specification signed and Witnesses cluding projections provided With horizonthis 6th day of December 1910. tal seats to support said vlaminare and projections forming vertically extending ribs en- DONALD M. BLISS. 5 gaging grooved portions of said laminac to Witnesses:

retain the two sets of lamin in properly FREDERICK BACIIMANN,

spaced relation, substantially as described. ANNA R. KLEIIM. 

